15-Crown-5 is a biochemical reagent used as an efficient phase transfer catalyst and complexing agent in life science research. It can isolate oxonium ion (H7O3)+ salts, particularly from tetrachloroauric acid solutions, and catalyzes the O-alkylation of sodium salts of carboxylic acids in penicillin and cephalosporin series, aiding esterification without acid. Additionally, it facilitates the Williamson synthesis of ethers with hindered alcohols and sodium hydride.
- Used with lithium aluminum hydride for reduction reactions in hydrogen solvents.
- Involved in the Horner-Wadsworth-Emmons reaction to prepare stilbenes from aldehydes.